harwood



(No Model.-)

J E HARWOOD TOOL GUIDE FOR SHARPENING LAWN MOWER KNIVES.

No. 462,435. Patented Nov. 3, 1891.

INVENTOR: %4MZ TW ATTORNEYS.

WITNESSES:

TATES PATENT OFFICE.

JOHN E. IIARIVOOD, OF SYRAOUSE, NE\V YORK, ASSIGNOR OF ONE-HALF TO JOHN A. LIGII'II'IALL, JR, OF SAME PLACE.

TOOL-GUIDE FOR SHARPENING LAWN-MOWER KNIVES.

SPECIFICATION forming part of Letters Patent No. 462,435, dated November 3, 1891.

Application filed July 20, 1891. Serial No. 400,043. (No model.)

To all whom it may concern.-

Be it known that 1, JOHN E. IIARwooD, of Syracuse, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in Gages for Sharpening Lawn-lllower Knives, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to a gage designed to be applied chiefly to lawn-mower knives for the purpose of guiding the file or analo gous abradingtool employed for sharpening the knife. Inasmuch as such knives are usually spiral shaped and are arranged to move in proximity to a stationary cutterbar, the sharpening of the knives requires great accuracy and care, not only in regard to the bevel of the cuttingedge, but also to maintain the entire length of said edge in a cutting position with the edge of the'stationary cutterbar during the movement of the former over the latter, and for that reason the sharpening of said knives is usually effected in machine-shops.

The object of this invention is to provide simple, inexpensive, and convenient means for enabling persons to sharpen their lawnmower knives at home and directly on the machine; and to that end the invent-ion consists of a gage composed of a tool guide adapted to ride on the edge of the knife to be sharpened and provided with a brace bearing on the side of knife and sustaining the guide in a uniform plane, hereinafter more fully described, and set forth in the claims.

In the annexed drawings, Figure lis a perspective view of my invention. Fig. 2 is a side view of the same mounted on a knife, and Fig. 3 is a vertical transverse section illustrating more fully its connection with the knife and the manner of using it in the operation of sharpening the knife. I

Similar letters of reference indicate corresponding parts.

a represents the guide in which the file or sharpening-tool e is placed, as indicated by dotted lines in Fig. 3 of the drawings, said guide consisting of a suitable bed a, which serves to maintain the file or sharpening-tool in a uniform plane during its operation, and

slightly into the bottom of the flanges a a and is of a width to allow the said guide to ride by the bottom of its flanges on top of the cutting-edge of the knife O and the latter to protrude slightly through the slot, as illustrated in Fig. 3 of the drawings. From the guide a extends downward a breast or brace Z), which in the operation of sharpening the rotary knife rests against the side of said knife and thus prevents the guide a from tilting in one direction. The brace I) is provided with a shoulder c, by which it rests against the underside of the stationaryknife G of the lawn-mower. The guide ct is thus firmly sustained in a uniform plane.

In sharpening the knife O the guide a. is slipped successively lengthwise of the two knives C and C to permit the file or sharpening-tool to be operated on different parts of the cutting-edge of the knife C.

What I claim as my invention is l. A gage for sharpeningknives, consisting of a tool-guide adapted to ride on the edge of the knife and provided with a brace adapted to bear on the side of the knife and sustaining the guide in a uniform plane, as set forth. 8o

vided with the shoulder c, substantially as and for the purpose set forth.

In testimony whereof I have hereunto signed my name this 18th day of July, 1891.

J OIIN E. IIARWOOD. [n s] fitnesses:

MARK W. DEWEY, J. J. SAASZ. 

